With fowlr, the main thing is to have adequate filtration to take care of the bioload. For the fish you specified, the bioload won't be that high, so prob a single powerhead (maybe a maxi-900) would be adequate. Lighting can be a simple single tube that comes in most hoods as nothing will need high light.
You won't need a sump either unless maybe if you go with a more predatous fish. A pred will have a much higher bioload as usuallyt hey are messy eaters and cause a lot of food bits to be dispersed through the tank. You would def want to get a skimmer too if you were going with a pred tank.
If you have enough lr, then you won't need a standalone filter. But you could still have one like a hob filter as I have for a little dark refugium for benficial sponges and fans to grow. They will apreciate the dark and secluded housing with a constant water flow to feed them